O'Reilly's "Getting Started with Raspberry Pi" is a really great book. I don't know where to start so here's a list of things I liked.

From Make:Projects which is very practical
Starts out strong - each part of the Pi and what you need to use it
Good tips - how to connect via wifi and without internet
Nice troubleshooting section
Practical examples from a "hello world with leds" program to building a web-lamp
A whole chapter on webcams. [This is the project we wanted it for]
Coverage of basic Linux, Python, breadboards and more. And for making it easily skim'able so you didn't gloss over important parts hidden in things you already know.
Less than half of the price of the Pi itself ($15 for hard copy and less than $10 for e-book)

I used the book and Pi to help out with Raspberry Pi on a local FIRST robotics team's robot for camera vision. The book was really helpful and the robot will most likely be demo'd at the NYC 2013 MakerFaire. So special thanks to O'Reilly for the book. You'll be seeing the benefits in practice in the fall! And good luck to the team in competition. I hope the Pi brings you great luck.

---
Disclosure: I received a copy of this book from the publisher in exchange for writing this review on behalf of CodeRanch.